/Engine/Source/Runtime/RenderCore/Public/Shader.h
Can be overridden byFShadersubclasses to modify their compile environment just before compilation occurs.
static void ModifyCompilationEnvironment ( const [FShaderPermutationParameters](API\Runtime\RenderCore\FShaderPermutationParameters) &, [FShaderCompilerEnvironment](API\Runtime\RenderCore\FShaderCompilerEnvironment) & )